Hey all, ive recently bought a full race GT kit for my b18c powered civic, installed and all running well exept the mechanic said the wastegate spring was an 11psi spring, and he said no problem, he'd just shorten it to run less boost. i said no worries to that and it was done.
Problem being, the boost doesnt really seem smooth, it starts at 6psi then as the revs rise, the boost rises, it stops at 7.5psi then at about 7500rpm it spikes to 8.2psi or so...
Someone told me i can just get a new wastegate spring meant gor 7 or 8 psi and it should run more smooth... is this correct? if so, would i need to re tune? has any one changed springs before?
Another thing, if i get a 7or 8psi spring, if i were to up the boost to 9 or 10psi, would i need another spring again?
thanks guys :D
Christian

 

you need a boost controller and a 7 or 8psi spring

the lowest boost you want to run

 

Cheers mate, but if i got a 7-8psi spring right now, would i need a new tune?

 

anyone?
also, anyone know how much a new Tial 8psi spring will set me back?

 

It could be that the manifold is causing the boost to creep. If it creeps from 6psi to 8lbs, I would just leave it alone.

Adriano

 

ebay?

 

The manifold is probably causing some creep. Happens to many ramhorn manifolds (I'm assuming this is what you have). They can creep anywhere up to 4 psi over the wastegate spring sometimes.

If the fuel/ign maps have been covered for all pressure readings, you shouldn't need a retune. Not sure what your tuner has done though, so check with them on that one.

 

but i have a Full Race manifold lol i thought they were supposed to be the best

 

they are but that doesnt mean that you will have perfect consistency in all instances. what turbo are you running? a 38mm wastegate may be having trouble regulating a large turbo at such low boost levels.

also you make it sound like the tuner physically cut the spring. if so, bad idea and thats probably causing some issues as well.

 

im running a GT28RS with a 44mm wastegate...
and i figured it may be the cut spring, thus why i posted the thread hahah i just wana know if ill need a retune, and how much itll set me back :p

 

It IS the cut spring. Your buddy cutting it didn't do it correctly. Think about back in the day when people used to cut OEM spring coils to drop their cars height. What happened? Because of the changed coil, the car bounced all over the place and vibrated like a chimpaze in heat.

If you're tuned to over 11psi, you've been tuned from 1psi to over 11psi. That means you can run 8psi without a new tune, as long as you keep the same turbocharger and injectors.

Get the right TiAL spring, get a boost controller, enjoy the car.

 

oh i do enjoy the car :D id just like to make it faster haha but before i raise the boost, i think an LSD is in order :p
The car is tuned for 7.5psi i believe as thats what it runs at most of the time, its just the fact it starts at 6 and rises is what id like to fix first so it feels smoother....
IF i whacked a 8psi spring in, would the tune make much of a difference for the .5 psi?
Im just paranoid as ive never boosted a car before and as you would guess, i have spent ALOT of money on my setup LOL
Thanks HEAPS "TheShodan" :D

 

should i post my dyno sheets?

 

 

thats not the total power i made... i made 170kw but he printed these ones as he said they look the smoothest...
170kw or 228hp doesnt seem like much to you guys, but apparently our aussie dynos dont read as high as your american ones...

 

I looked at the TIAL website, it seems i can only get a 7.252 PSI or a 8.702 PSI spring... judging by my dyno papers etc, which one would be the best? if i could handle the 8.7psi spriing that would be great! BUT if it will jeopardize my tune and risk damage at all, the 7.25 spring will be purchased

 

if you are concerned then stick with the lower psi. you can always increase it later with a boost controller. no one is going to definitively tell you that your car will be safe at a certain psi because we dont know how it was tuned.

 

i love it when you talk dirty

 

smaller spring and boost controller. you're going to creep no matter what. Not much. But it's going to happen. The key is to regulate how high it creeps and what you're going to do to stop it from going higher.
7psi spring and boost controller. Also a tune on both wouldn't be bad either.

 

thanks guys :D looks like ill get the 7.2psi spring, i may loose a little power up top, but ill gain power in the lower ranges so that will even it out...
just to confirm, with the proper 7.2psi spring will that definatly fix the low boost at low rpm?

 

I don't understand by your meaning of the word "fix". It will keep the amount of boost more stable, than if you had a cut spring. As mentioned, you can find a boost controller to change any setting up to 2.5* the spring, so about 18psi

 

Just so you know tial offered to replace my spring for free if I sent them my old one. Give them a call, they may be able to swap it for ya

 

**not if its been altered though** we will not swap cut springs

 

thanks Shodan! thats wat i was after, to keep it more stable... ahh it doesnt bother me, im all the way in australia, too much hassle to send mine back there, they are only cheap anyways

 

MTQ should have the springs